2020 Japanese Super GT

[helgi]

Originally Posted by Japanese Samurai

The cause of the retire of Subaru BRZ GT300 was a malfunction of the exhaust pressure sensor.
What seemed to be the engine fire was due to the fuel being over-injected into the exhaust.
https://twitter.com/SUBARU_STI_MS/st...33936741945344

I'm so sad for them. I've enjoyed reading series of articles in "Autoprove" about their machine. I wish there is the same quality (and quantity) articles about other cars (and in English too).
https://autoprove.net/subaru/sti-technology/192744/

[S griffin]

Seems a minor thing can cause a major problem. Shame after all the work they've done to get the Scooby out. Still we have the rest of the season to see what they can do compared to everyone else

[Japanese Samurai]

Autoprove Subaru BRZ GT300 inside report.
https://autoprove.net/subaru/sti-technology/192935/

*Cause of retirement
Exhaust pressure sensor was causing a short circuit.
This reduced the supply voltage to the fuel pressure sensor, which had the same power supply as this sensor.
If it completely disconnect or short circuit, it can run in fuel-safe mode. But this time it was controlled with a low voltage that didn't reach fail judgment, so the fuel supply increased significantly and the engine stopped and excess fuel flowed to exhaust manifold. This caused a flame.

*Measures
There are engine control sensor and logging sensor, but in order to avoid the risk that occurred this time, they decided to disconnect the logging sensor in the race.
In other words, there is a demerit that engine data of the final race cannot be acquired.

[Japanese Samurai]

Wind tunnel test movie of GR Supra GT300.
https://www.youtube.com/watch?v=LbHfkUEJLgI

(25% wind tunnel of Yajima Industry?)
http://www.syms.co.jp/business/randd/fuudou/

[Japanese Samurai]

*There seem to be two wind tunnel models with different scales.
*The larger model has an early exhaust outlet.

[S griffin]

Better to have two as a backup and take no chances. Could be very useful

[hvr777]

https://supergt.net/tandds/entry/2020/Round2/gt500

Sena Sakaguchi will be substituting Heikki Kovalainen for Round 2 at #39 TGR Team SARD,
his place at #96 K-Tunes Racing (GT300) will be substituted by Shigekazu Wakisaka, driving alongside Morio Nitta.
Last year, Shigekazu raced with #52 Saitama Toyopet GB.

[Japanese Samurai]

Autosport web is reporting reason of inferiority of Nissan GTR.
https://www.as-web.jp/supergt/604475?all

*Tsugio Matsuda says that they can't find basic set-up yet. Quintarelli says that they can't turn in slow speed corner well.
*Motohiro Matsumura (NISMO exective director) admits that the L/D value of the base vehicle is inferior to rivals.
*Hiroaki Odajima (Michelin) says that they had to choose race tires of 1st round from they have already developed in June due to lockdown.
*In contast, Katsumasa Chiyo (#3) says that their task is to balance peak performance (qualifying pace) with race pace. They are not bad at slow corners. #3 and #23 are trying different direction car set-ups.
*Quintarelli says that as the season progresses, they may move on to the better set-up of #3 or #23.
*The result of the first round is not reflected because the tires for the 2nd round have already been decided.

[S griffin]

Wow, that's a lot of reasons, although it's a good job they've identified them early. It's going to really tough to get all those sorted. Will be a long season for them. They need to have their wits about them to turn it around. Best of luck to them anyway

[Japanese Samurai]

jp.motorsport.com is reporting Naoki Yamamoto interview.
https://jp.motorsport.com/supergt/ne...-race/4843829/

*1st round was a perfect defeat.
*To be honest, the Toyota squad emphasized long runs from the time of testing, so I thought their race pace would be good, but it was more than expected.
*We used tire grips to cover machines that were nervous moving. However, in the latter half of the stint, if the tire grip was lost, the car would behave in a nervous moving, and it was difficult to stay ahead of the rivals.
*A pickup phenomenon has also occurred, and it has become clear that the long-standing problems of NSX-GT have not been solved. So we may have to change some of the know-how we have accumulated so far.
*I think we will not lose if we can show performances like practice sessions and Q1 also in the final race. The fact that we cannot do that may mean that we still have a low level of understanding of the machine.

*When analyzing the first round, NSX overwhelmed the practice session and Q1, but Supra suddenly marked the best lap time in Q2. It was like they used something "magic". Their pace up in Q2 was hard to understand.

[Japanese Samurai]

GTA publishes special bulletin for 2nd round.
https://www.as-web.jp/supergt/605973?all

*All GT300 cars must exchange four tires when changing drivers at the pit stop.
This does not apply when starting with wet tires during the final race.

*The JAF-GT300 is exempt from using the fuel flow restrictor.
For JAF-GT300MC, the size of the fuel flow restrictor will be expanded (27.5 mm to 31.2 mm).

[Japanese Samurai]

This rule change during the season is very questionable.
This is because there should be a team that has developed tires on the premise of fuel only pit stop strategy.

[hvr777]

Originally Posted by Japanese Samurai

This rule change during the season is very questionable.
This is because there should be a team that has developed tires on the premise of fuel only pit stop strategy.

Yeah, I think it's too soon to make changes on such rules. IMO it's still sensible if they want to apply it next season.
Besides, from my POV this rule isn't about safety improvements which is need to be applied ASAP.

[bentley speed 8]

Originally Posted by Japanese Samurai

This rule change during the season is very questionable.
This is because there should be a team that has developed tires on the premise of fuel only pit stop strategy.

I agree it's a real bummer, as nobody can now gamble on fuel only stops or by changing only two tires. Takes out a lot of strategy aspect that makes gt300 interesting to watch

[Japanese Samurai]

Team MACH (#5) owner Tetsuji Tamanaka complains this time regulations change on the his facebook page.
https://pbs.twimg.com/media/EePIy6gUYAE_G0x?format=jpg

I was surprised at regulations change only one week before race.
I couldn't find a race in the world that would change regulation just before the race.
The tires to be used in this race have already been decided one month ago due to the tire manufacturer's manufacturing capacity.
So it's a crisis for a team with a fuel only pit stop strategy.
I can understand the regulation revisions decided before the season, but this regulation revision will ruin the strategy of the team and the fun of the race.
Race fans are looking for unpredictable and interesting races.
Is it interesting that a fast machine only exchanges four wheels and wins?
It's a race for all the fans.
What do you think guys?

[hvr777]

What makes me more curious is, who urges such sudden regulation changes?

[Japanese Samurai]

I suspect Yokohama lobbied with a flickering withdrawal from GT300.
Unfortunately, the truth cannot be told by Bandoh san.

[Japanese Samurai]

Autosport is reporting GT300 4 tire change mandatory rule explanation.
https://www.as-web.jp/supergt/605986?all

Since multiple teams took the fuel only pit stop strategy in the first round, tire troubles occurred multitime due to extremely low tire internal pressure.
Seeing these situation, Chairman Bandoh seems to have proposed to the team and tire manufacturers the obligation to replace four tires.
The proposal reason is to eliminate tire trouble and give priority to safety.
This proposal was decided after getting the approval of the participants after going through the proper processes such as entrants and manufacturers.
The bulletin this time is only for the second round, and after the third round, it will be decided after a meeting again.

[Japanese Samurai]

Tsutomu Tojo (Team Tom's engineer) says he agrees with 4 tire change mandatory in GT300.
https://ameblo.jp/tsutomutojo/entry-12614435875.html

Crashes due to tire bursts are a serious problem for tire manufacturers.
And race interruptions due to tire bursts ruin the race.
And above all, since safety should be the first priority, he thinks that it is correct to oblige to replace four tires during pit stop at Fuji and Suzuka,.

[Japanese Samurai]

Hoppy team Tsuchiya 1st round race report
https://www.as-web.jp/supergt/606661

*This year's theme of the team is tire development.
*Yokohama sent a young engineer, so the team will develop tires from scratch.
*It takes 3 years to become a champion as usual, but Takeshi Tsuchiya wants to achieve it in 2 years.
*In the race, slow puncture occurred on lap 32 and they made an emergency pit stop.
*They knew that rear tires might not last, so they were able to collect good data.
*Kimiya Sato sensed a slow puncture and returned to the pit without breaking the car. He did a very good job.
*Team Tsuchiya has never used a data logger before, but this year it hires a data engineer and uses log data.
*Takamitsu Matsui struggles with driving of Porsche (rear engine car). He says that driving style that lowers bottom speed and uses inertia to corner is required.
*Takeshi Tsuchiya says that if Matsui can make Porsche run faster, he can surely extend his career as a pro driver.

[hvr777]

Originally Posted by Japanese Samurai

Hoppy team Tsuchiya 1st round race report
https://www.as-web.jp/supergt/606661

*This year's theme of the team is tire development.
*Yokohama sent a young engineer, so the team will develop tires from scratch.
*It takes 3 years to become a champion as usual, but Takeshi Tsuchiya wants to achieve it in 2 years.
*In the race, slow puncture occurred on lap 32 and they made an emergency pit stop.
*They knew that rear tires might not last, so they were able to collect good data.
*Kimiya Sato sensed a slow puncture and returned to the pit without breaking the car. He did a very good job.
*Team Tsuchiya has never used a data logger before, but this year it hires a data engineer and uses log data.
*Takamitsu Matsui struggles with driving of Porsche (rear engine car). He says that driving style that lowers bottom speed and uses inertia to corner is required.
*Takeshi Tsuchiya says that if Matsui can make Porsche run faster, he can surely extend his career as a pro driver.

I'm interested that Tsuchiya Engineering used to work on its car without data logger before. How can they understand the way the car behave on the circuit?

Other than that, I guess the team must be having steep learning curve with its new Porsche.

[Japanese Samurai]

Tsuchiya is an "analog" man, so race week set-up is made by driver's infomation only.
Originally, there was only a left damper stroke sensor in Hoppy 86MC.
https://twitter.com/TsuchiyaTakeshi/...08942510858241

As for Tsuchiya, they make very fan friendly and informative report.
The race report that I translated also has a unique style that Hoppy Porsche in first person looks back on the race (in Japanese).

[Japanese Samurai]

Autosport web is analyzing strongness of GR Supra and the best answer for Class one.
https://www.as-web.jp/supergt/607789?all

*Top six of GT500 were Bridgestone users.
It's true that BS had an advantage, but Supra chose a harder tire than NSX, which seems to have adapted to the high road temperature.

*Supra overwhelmed NSX at maximum speed.
*Hirakawa says that Honda engine has good acceleration from low speeds, Toyota engine has good continuation of high speeds, and it has the characteristic of not slowing down even in high temperatures.
*TRD focused on improving cooling performance and maintaining proper water temperature for this season.

*Many of the GT500 cars this year have adopted high rakes like DTM cars.
By adding rake angle, the ground effect is increased and downforce lost due to the revision of the regulation can get back.
*Above all, it seems that Supra and NSX were developed on the premise of adding a rake angle.
*The disadvantage of high rake is the increase of drag.
However, engineer Tojo (Team Tom's) says that high rake is effective if it can be covered by cornering speed.
He says that Supra was designed for high rake set-up, so the speed loss is small. Therefore, in Fuji, both high rake and low down force set-up with flat rake are possible.

*Rookie racing (#14) is actively trying the high rake set-up.
*Cerumo (#38) and Bandoh (#19) also tried high rake, but it's not as good as Rookie.
*SARD (#39) returned to flat rake because high rake did not work, but the optimum solution was not found.
*On the other hand, Keeper Tom's (#37) was not as high rake as Rookie, but straight and cornering were fairly fast.
*Regarding the downforce balance, Keeper Tom's was closer to the front and au Tom's was closer to the rear.
*Engineer Abe (#36) frankly admitted that he completely lost to #37.

[canaglia]

maybe I'm wrong, but isn't high rake angle used to reduce drag?
In f1 during late seasons, cars like ferrari, renault or pink force india always got really high top speeds due the high rake set-up.

[crmalcolm]

Originally Posted by canaglia

maybe I'm wrong, but isn't high rake angle used to reduce drag?
In f1 during late seasons, cars like ferrari, renault or pink force india always got really high top speeds due the high rake set-up.

I think it is primarily aimed to increase the ground effect of the front wing, and to artificially increase the volume of the rear diffuser.